For organic light-emitting diodes, efficient energy or charge transfer from a host species to an emissive guest species is desirable. To achieve this, host materials having a high triplet energy relative to the guest species and high thermal stability have been pursued, but to date remain a challenge to develop. Various classes of materials have been studied for use as host materials, including carbazole-derived materials. While many carbazoles have sufficiently high triplet states, they are often undesirably crystalline, insoluble, and difficult to process.